gasoline drainback

gotyourgoat · Apr 17, 2020

Bextreme04 said:
Man, there is a lot of bashing of the OP going on in this thread. I'm struggling to see how just dismissing what she is saying and repeating to go back to all stock is helpful.

First of all, she can't go back to the factory hardline, she has an edelbrock carburetor which has a different inlet that is located in a different spot. Telling her to buy a $400 carburetor to replace one that is working perfectly fine is ridiculous.

Secondly, I have had a very hard time finding an OEM mechanical pump with the correct fuel pressure lately. I bought a quality AC Delco replacement pump when I rebuilt my fuel system on my 80' K20 and was having a lot of problems. Fuel senders replaced, both tanks cleaned, new hose, new fuel pump, new fuel filter, and rebuilt the original Quadrajet. I could not for the life of me get the idle mixture leaned out and it ran pig rich all the time. I finally checked the fuel pressure and it was running 8psi at the low end and spiking up off the gauge that stopped reading at 12psi. The quadrajets really prefer to be down near 5 psi and certainly can't hold the seat closed at 8psi let alone 12 or more. This was all quality factory replacement parts.

Rather than spend time and money replacing pumps until I find one that puts out the exact amount of pressure I want. I put a filter, check valve, and adjustable regulator in line between the pump and carburetor and low and behold I was able to dial the fuel pressure down to about 5.5 psi and dial in the carburetor perfectly. My gas mileage went up about 3 mpg, it starts right up every time cold or hot, and drives much better than it ever did before.

How about we start bashing you?

The original post made no mention of which carb she is running. I never told her to buy a new carb but thanks for putting words in my mouth.

She probably already has a pile of quadrajets laying around anyway. Have you heard the list of vehicles and hoard of parts she has on the family farm?

But yeah, I'm saying get rid of everything between the pump and the carb.

AuroraGirl · Apr 17, 2020

It made no mention because the fuel isn't draining In the carb it's draining back down the line. Hence drain back. Seriously, if you don't have anything positive to say you don't need to post. Demeaning me for not understanding every word said or asking for clarification or me trying to understand your train of thought is unecessary. Had you asked these questions I would not be looking down to any of you, rather try to help. And good thing I'm not in the northwest or a democrat, I guess. I have nothing between my fuel pump and my carburetor other than fuel line and a fuel filter.
I am trying to understand the need for a new hose, which I'm entirely open to getting if I can work with it, because the flare on the original hard line does not leak and holds my rubber line on just fine. For sale of cleanliness and threads, I'd honestly like a new line, yes.

I never had a 4 barrel quadrajet on this engine, which is why I asked for a photo of your rig so I can determine if it will clear my setup.

SirRobyn0 · Apr 17, 2020

broketiredugly said:
idiots always come from the northwest, or the great north? is it a cold thing, or a cabin fever thing, or just a democrat thing?

General rant feel free to flame this **** out of me after I say it. In a lot forums comments like the above would get you warning and a delete of the post by a moderator, and if you kept it up you'd get your account locked, but not here, here it is apparently perfectly acceptable to insult, be little and just generally act like a jerk. You have no idea how much you just insulted me and anyone else that happens to be from the NW or democrat. As much as I enjoy helping and being helped on these forums when a thread dissolves into BS like this it's an embarrassment to everyone here. Thanks for that.

Why do we have to post insults?

Nonstop · Apr 18, 2020

Look - here is my view. Do with it what you see. Been going through similar **** with drain back on my big block. Are you insisting on running the Edelbrock? If so, then do it. Not my thing, but it is what you want. So, moving on, take a measured approach. It sounds like there are 2 issues here being kicked around. Check the fuel pressure coming from the pump. What is it? No personal experience with the Edelbrock carbs, but have read and spoken to people, who all seem to agree it should be about 4 to 4.5 psi max for that carb. As for the drain back issue - I had rebuilt my quadrajet and sealed it up. Still drained back. Threw parts and time at it. Replacing gaskets, rechecking my work, etc. I was contemplating a check valve myself but had not done it yet. I recently replaced my fuel pump (on sale at rockauto) and it seemed to help quite a bit. Might check what pump Edelbrock recommends for their carbs and go from there. It ultimately could be the pump. The alternative is to just put up with it (I did it for years).

AuroraGirl · Apr 18, 2020

Nonstop said:
Look - here is my view. Do with it what you see. Been going through similar **** with drain back on my big block. Are you insisting on running the Edelbrock? If so, then do it. Not my thing, but it is what you want. So, moving on, take a measured approach. It sounds like there are 2 issues here being kicked around. Check the fuel pressure coming from the pump. What is it? No personal experience with the Edelbrock carbs, but have read and spoken to people, who all seem to agree it should be about 4 to 4.5 psi max for that carb. As for the drain back issue - I had rebuilt my quadrajet and sealed it up. Still drained back. Threw parts and time at it. Replacing gaskets, rechecking my work, etc. I was contemplating a check valve myself but had not done it yet. I recently replaced my fuel pump (on sale at rockauto) and it seemed to help quite a bit. Might check what pump Edelbrock recommends for their carbs and go from there. It ultimately could be the pump. The alternative is to just put up with it (I did it for years).

Yeah I want to stick with the edelbrock, it runs great with it and its a simple, clean looking carb. Fuel savings are not of import to me. Which with spreadbore are typically better. I get good power, too. Once its warm I think ill bite the bullet and try a pump first, without a regulator, and see what i get. Ill try to get a new steel line and fuel filter, as the filter has junk in it and the steel line may have buildup and crud, never know. Rn its not a big deal if it gives me grief starting, its not -30 and cold or snowing.

SirRobyn0 said:
General rant feel free to flame this **** out of me after I say it. In a lot forums comments like the above would get you warning and a delete of the post by a moderator, and if you kept it up you'd get your account locked, but not here, here it is apparently perfectly acceptable to insult, be little and just generally act like a jerk. You have no idea how much you just insulted me and anyone else that happens to be from the NW or democrat. As much as I enjoy helping and being helped on these forums when a thread dissolves into BS like this it's an embarrassment to everyone here. Thanks for that.

Why do we have to post insults?

Although i fully disagree with his politicizing and his general attitude, I would not support moderator action against him. It is of my deepest beliefs that peole should have the most freedoms possible unchecked and undisturbed. Yes, he is a rude *******, but we show we are better than him and we are right by allowing him to post his idiocy. Same concept as hate speech, we are civilized BECAUSE We allow dissenting voices, even if racist or stupid. Love the sinner, hate the sin.

Bextreme04 · Apr 20, 2020

gotyourgoat said:
How about we start bashing you?

The original post made no mention of which carb she is running. I never told her to buy a new carb but thanks for putting words in my mouth.

She probably already has a pile of quadrajets laying around anyway. Have you heard the list of vehicles and hoard of parts she has on the family farm?

But yeah, I'm saying get rid of everything between the pump and the carb.

Well, you are obviously going to do whatever you want anyways, so go ahead and bash away if it makes you happy. I didn't put any words in anyone's mouth, your own words are there for everyone to see. I'm not going to distract from her thread anymore, so I won't be back to look at any more nonsense posts in here.

I'm not here to argue with the trolls that apparently have nothing else to do during the pandemic but demean people asking for help, I came to help her with her question. @AuroraGirl feel free to PM me if you have a specific question or need assistance with anything.

AuroraGirl · May 24, 2020

Follow up: Since its been warm, consistently 50 degrees or more, even after a few days I only need a single pump to start the truck. After about 1.5 weeks it seems to need two, but it could have been maybe i didnt set the accelerator all the way to make it go to proper idle, maybe.

This is on the old fuel pump with my edelbrock, which I think kind of validates or at least supports my theory of cold was letting fuel drain back and thus requiring some cranking and more pumps. So far, at least 10 trys with waits of at least a day, most commonly 2-3 days, and the one at 1.5 weeks have been 1 pump and starts right up.

im still going to replace this pump, more black bits of rubber keep showing up in the fuel filter. Ill replace filter at the same time as pump, and I will install a regulator when I do so

Ricko1966 · May 24, 2020

I've bought 2 vehicles with edelbrock carbs on them, installed by previous owners, stock chevy fuel pumps, no pressure regulators, no check valves, no problems.I would not install a fuel pressure regulator, unless I verified the fuel pressure was too high.Even then I'd try a different manufacturer pump I have 2 chevy 350s running great with mechanical pumps and no regulators. I've had problems with regulators before it's just 1 more part in the equation.

Blue Ox · May 25, 2020

There are check valves in the fuel pump. Replace the pump and you install new check valves as part of the deal.

AuroraGirl · May 25, 2020

Blue Ox said:
There are check valves in the fuel pump. Replace the pump and you install new check valves as part of the deal.

Are you saying install an inline check valve in addition to the pump..? or are you saying by replacing fuel pump youre putting in new check valves?

Grit dog · May 25, 2020

^^Nooo, he’s saying spend $20 on a new fuel pump and be done with it.
Honestly you’ve spent more on internet bandwidth for this thread and gas starting the truck to see if it still starts, than a new pump would cost.
This is not complicated, at all, unless you continue making it out to be!

Where in Northern Cheeseland are you?
Have property in Park Falls still , spent lotsa time there. Sis lives in Eagle River.

SirRobyn0 · May 25, 2020

AuroraGirl said:
Follow up: Since its been warm, consistently 50 degrees or more, even after a few days I only need a single pump to start the truck. After about 1.5 weeks it seems to need two, but it could have been maybe i didnt set the accelerator all the way to make it go to proper idle, maybe.

This is on the old fuel pump with my edelbrock, which I think kind of validates or at least supports my theory of cold was letting fuel drain back and thus requiring some cranking and more pumps. So far, at least 10 trys with waits of at least a day, most commonly 2-3 days, and the one at 1.5 weeks have been 1 pump and starts right up.

im still going to replace this pump, more black bits of rubber keep showing up in the fuel filter. Ill replace filter at the same time as pump, and I will install a regulator when I do so

You could be right about the cold weather worsening the drain back, but also maybe the cold weather made it harder for the fuel pump to work correctly. I'm not saying that as fact, rather I'm putting it out there for your consideration.

Ricko1966 said:
I've bought 2 vehicles with edelbrock carbs on them, installed by previous owners, stock chevy fuel pumps, no pressure regulators, no check valves, no problems.I would not install a fuel pressure regulator, unless I verified the fuel pressure was too high.Even then I'd try a different manufacturer pump I have 2 chevy 350s running great with mechanical pumps and no regulators. I've had problems with regulators before it's just 1 more part in the equation.

@Ricko1966, A few years ago I would have said the same thing, but in the mean time I've had to install a regulator on my truck to keep the edelbrock from flooding. I guess I just want you to know that even though you have never had a problem with it does happen.

Ricko1966 · May 25, 2020

SirRobyn0 said:
You could be right about the cold weather worsening the drain back, but also maybe the cold weather made it harder for the fuel pump to work correctly. I'm not saying that as fact, rather I'm putting it out there for your consideration

@Ricko1966, A few years ago I would have said the same thing, but in the mean time I've had to install a regulator on my truck to keep the edelbrock from flooding. I guess I just want you to know that even though you have never had a problem with it does happen.

Ricko1966 · May 25, 2020

Yep and I've had a pressure regulator starve an engine.Same car same engine 2 different regulators I worked fine 1 starved the engine and in the end neither was needed.I 've had pumps with too little volume.Ive had pumps with too much volume which creates too much pressure, shortened the push rod too lower volume and thus lower pressure.Ive run return lines with a tee straight leg goes straight through to carb(path of least resistance)side leg is the return and use a restrictor in the return so carb is truly path of least resistance,in retrospect I think I could have used a fuel filter in the return line as my restrictor.I used brass stock drilling different size holes tell I had what I wanted in the return.The float bowl fills closes the needle, fuel goes out the tee back to the tank.Many ways to skin a cat.Id keep as many variables out of the equation.Start with a pump.Its cheap and easy.

AuroraGirl · May 25, 2020

Im near Eau Claire. Another member here is up by Hayward. And I think Ill try a fuel pump first then and see how it behaves. Considering its not leaving property soon and Ill have plenty of idling and running before it will to test to see if I run into fuel pressure issues.

gasoline drainback

gotyourgoat

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AuroraGirl

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SirRobyn0

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Nonstop

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AuroraGirl

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Bextreme04

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AuroraGirl

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Ricko1966

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Blue Ox

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